1. Field of the Invention
The present invention relates to recreational vehicles and especially to a system for leveling and supporting a recreational vehicle with positive and negative air pressure.
2. Description of the Prior Art
A variety of recreational vehicles are available on the market, including small and large campers for attachment to the back of a family automobile for camping for short or extended periods of time, large motor homes, and fifth wheel campers, which do not have front wheels, and are suspended by a fifth wheel to the back of a pickup truck. This latter vehicle requires front end support when disconnected from the truck. One of the problems encountered by most recreational vehicles is supporting the front end or tongue of the camper when the recreational vehicle is disconnected from the family car or other towing vehicle. The support must be adjustable to allow the vehicle to be adjusted for different heights to maintain the inside of the recreational vehicle level. In addition, on the smaller campers, the springs are such that the campers tend to be unstable, and shake considerably when positioned in a campground, or the like. These problems are dealt with by hand actuated jacks, which may be placed under the tongue of the camper, or mounted to the front portion of a fifth wheel camper, and which may be hand actuated to raise and lower the front portion of the vehicle. On smaller campers that tend to be unstable, a series of smaller hand operated jacks are sometimes positioned on the four corners, and each jack operated to get the camper level and supported by the jacks so that the camper will not rock when walking from one side of the camper to the other. In addition to hand actuated jacks that are commonly used or supplied with recreational vehicles, auxiliary jacks have been available which are actuated by electric motors for raising and lowering a portion of the vehicle. These require connection to electrical power, and are expensive to purchase as an option to the recreational vehicle. Finally, large semi-trailers have fifth wheels having air over hydraulic jacks for supporting the trailers when disconnected from the cab portion, which are actuated by the truck's air system.
Typical prior patents may be seen in U.S. Pat. No. 3,350,063 for a hydraulic jack for camper bodies, in which a hydraulic jack may be swung from the side of a camper body mounted on a pickup truck for supporting the camper body while driving the pickup from under the camper body, and in U.S. Pat. No. 3,415,490 for a lift jack apparatus having a hand actuated jack for supporting camper bodies. U.S. Pat. No. 3,360,141 teaches a container lifting means and method using a hydraulically actuated container lifter, while U.S. Pat. No. 3,338,554 illustrates a screw jack actuated from a pickup loaded camper body for lifting the camper body portion.
The present invention, on the other hand, provides a simple series of air cylinders permanently attached to the recreational vehicle and which may be telescoping, so that they are permanently locked into position, and which can be raised or lowered individually by the positive and negative air pressure applied to each individual cylinder. The cylinders are controlled by having each of the valves for each of the cylinders mounted adjacent each other and having an electrical switch mounted adjacent thereto, which actuates an electrical compressor in a forward or reverse direction for generating a positive and negative air pressure in a manifold, which is then applied to individual cylinders for adjusting the cylinder, and thereby allows the raising of the cylinder when needed.